Nitrogenase molybdenum-iron protein (MoFe protein) (MoFe protein)

The Nitrogenase molybdenum-iron protein (MoFe protein) is the catalytic component of the nitrogenase enzyme system, primarily found in diazotrophic bacteria and archaea such as Azotobacter vinelandii (UniProt: P07328, P07329). It is an alpha2beta2 heterotetramer that contains two unique metal clusters: the P-cluster ([8Fe-7S]) and the iron-molybdenum cofactor (FeMo-co), which serves as the active site for substrate reduction (PubMed: 1313187). Its primary biological function is the reduction of atmospheric dinitrogen (N2) to ammonia (NH3), a process essential for the global nitrogen cycle and the production of bioavailable nitrogen for all life forms. The MoFe protein works in conjunction with the Fe protein (Component II), which provides the high-energy electrons and ATP hydrolysis required to drive the reduction process. While the MoFe protein is not a target for human therapeutic drugs, it is a major focus of agricultural biotechnology for developing sustainable alternatives to industrial fertilizers. The enzyme is highly sensitive to oxygen, which causes irreversible oxidative damage to its metal clusters, posing a significant challenge for its expression in aerobic organisms. Research into its mechanism often utilizes inhibitors like carbon monoxide and cyanide to probe the electronic states of the FeMo-cofactor during catalysis.

Other names

DinitrogenaseComponent I of nitrogenaseNifDKNitrogenase molybdenum-iron protein alpha chainNitrogenase molybdenum-iron protein beta chain

Not applicable as there are no known therapeutic drugs targeting this protein; however, its catalytic mechanism involves ATP-dependent electron transfer from the Fe protein (Component II) to the FeMo-cofactor (M-cluster) for the reduction of dinitrogen (N2) to ammonia (NH3).